msm: mdss: add aux read/write support for hdcp

Hookup sink's aux addresses for data read and write to be used
for hdcp 1.3 authentication so that hdcp 1.3 state machine can
dynamically select sink addresses for different interfaces.

Change-Id: I4ef01c7bdb9af770ea3014bd6e63d3c17b0cfa47
Signed-off-by: Ajay Singh Parmar <aparmar@codeaurora.org>